SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baf7760c080f4c412503819eb513c5fbe55311ce4cf9903a7372fd2937a013f2' 
  AND token = '1C2PK2tw8keuVTeo81zOLGu0+iCJayH9y3V8Y9NmAo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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