SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14946d4ca6a008509b2d28b8f9a071aaacb17bf3393985987ae2e0ed71d5b06f' 
  AND token = 'z8BZFp6FxrAomgyUvJjDrdh9B2YDspXrzDZC64RI42M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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