SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '381af42b7ddb1b86b5aebad9c98281717158f70ef6ad3a58f95dcb77a294066a' 
  AND token = 'pfsEcZOn926gKRF6BeqvjMID6MQl3DzHnxyQstT047w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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