SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d1de30460801f8e35d8bd9f82806f8c51dbb45ee98e0bfe672ff9b0a0cf9238' 
  AND token = '+T+Wb0FtZBs1/0y1XBMQgaUAts5apldXsAzxq0qiHjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}