SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '18b3cdbce468c6f1957916c1e67d2338bb72ad69617f93d84fd56f3cd441e329' 
  AND token = 'QBNSI5LxX6hNzwS2Wer//2YobPFUqRBtkew6bQqAr+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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