SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d45467ae95c89b3f5a4723cc3125ff321ce0ea4f69499cbc3252ff79a890648' 
  AND token = 'xoJmJskEVzHgmHkBPzXITZT0EL+XbjWss8KMJWum6yc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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