SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b13388deb17bbc43a52cb2ecf3e1f363a5df5bc4d8f5cc4a668bacfa5afb3a9c' 
  AND token = '2Hutcnj8ltkrDoBUX0Ww7fXBfbkJ5+y9JpnxxNKpqfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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