SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faa8dcf9a38a73a5be02d6926ec7e6f03e208c5341ee09e80d5eaa727d37048e' 
  AND token = 'I2jUIjepsx0kmaJV+z6v1reyH5lTXIYQevII/3LQoIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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