SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18790a9445e77c86c0aa6e038f85648742f9959cdb53b61d3180b9fd1910b262' 
  AND token = 'qHQ/nsfZR8AycjceF8MbVPAVSypYYZJrMVnePjff8yQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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