SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e5915a5a9431ff4c686a2efda1f8c5f83bdd4f6f4bb16a26268b149ad8e1ca' 
  AND token = 'Sip7oKEBj6mBnOIDSMQC1eZKHXYn+vXuEfrvbt5hNMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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