SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a478206afaf39051cb812b5b91e852ece7a96e92df38754d32a6b778dfd919b' 
  AND token = '3qpodmNiHQPIPCcnsVK+BU09y2Pqn+1wicZ/pqgqzBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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