SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '129eac269fa1b6f731dc2d78e51753bfb1cad446b2035a72e8076f2f0ecd00dc' 
  AND token = '3DcfzbSU73RzamfuyC3BAd3EVLArl9Gkm+2cfEvM1N0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}