SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f879215ec60075ae15144ddc9f17ef93b076573ce009dff672ca71466a3df5cc' 
  AND token = 'gcdGx9BFtajaz7KZCfp/jgv+tkjXN2UoFMEiwjJTlFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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