SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c992a5f35fccbb40ccebc415d6f299ddf6f7ca96d12dc098d04437264684fd50' 
  AND token = 'FD8p2wg3g5inKUl6TNSMvtt3IcRz+GJJR9XG0W9Ms0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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