SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fac2011de6c29c202cda82df7d4adbf13e66062b9ba0c40803668c39162d02d' 
  AND token = 'FZ8cx6bZ4ybmxs67OS22TOOR6902FDCPfFt+nzy2btY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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