SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc7763c24e266415341eafc4a630d9a55436e591403d24e08e055c4cc2df3469' 
  AND token = 'uEZWJC1lxKX4PC9rfQf8XnH4rfQsZFZDjaoLBX63A0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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