SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee66937ce4dc0632a934b364ab99a5761c95e99541d57151a5cb5adb450d0122' 
  AND token = 'F4YWPYf0g8tZeZkJ9IknWAXACOukmTPxKq9aeUcQBMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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