SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c76b04d6d3a4e3897725021bdfe5dea1c897e3f3b08622b409f9e81743cb1df' 
  AND token = 'QZd1sm2BWTbJKaOtNGCGzzJb/zVfPbqzaqUzBpUDnw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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