SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a4204ad5cdac8739cf624cb5f5d0555a4f9955b1361bf5f0f99beae922d155a' 
  AND token = 'noXpy6OCSjhey8hr8GbVSZTDXatguvNxdcnCeWl+aR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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