SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1abc7707a99069e548096f56aa9737c867cec9c444c2fe8c677285199427c50c' 
  AND token = '8ISPdM6+fCfmSMaTmd7x3BSwFTMKjI1LHiJYYJ7qbUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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