SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cf5cdb78e299856068360a5553a76e0df5a0f8a20053808628f036fb8fe9c1b' 
  AND token = 'ZT/4uoVp4Vs1Jy3t/OCoO2Q5C77gGzXXIhw1YDnOjEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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