SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '466e18c1aab1f82045d765a59a20a0dfeed31664510cf8c989415bb6df9a6580' 
  AND token = 'C8RW+I2f5QyPaInaQA7LkKdirRmqP3GqEDtUU2Z8c1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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