SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fde249823cc5c8b2ae4f8502e47c45715c812bf696373d8815198a27ae84402b' 
  AND token = '6vw+8SFsQv0SC0b9KVn9KjyBKp4wvCcjRBABMtg3Igg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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