SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cf12db76a7f4b5b3251b0ec38a7df83485b634a9ac9aa8ec2f89d74263b16dc' 
  AND token = 'ifK9DoVU8jdW4mnQyDHGyeYhIb0ZzN+LtAiJfxrUjeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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