SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7de37c56bbead5ea7b60f87e34e20c73296a9032029828abe98ed6cb2121e52c' 
  AND token = 'FNH+G2oYfrHKvXMFrZrKMxoiMJeI1CbF0VEYGgzv24c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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