SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92b7ece6cf9d951043a79a9f11a41310cba57270ec9789ac53d117f22452b4ef' 
  AND token = 'foDnHEBp/s8VZ3xOM20cabCgpU9uv2Iy6THT0Cy/bYw=' 
  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"
    }
  }
}