SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a0a162712795acb8cefab148c43596c56e4660fd976513ffdd08fd0e012404' 
  AND token = '7y0GtIy0UgxeuZxEEuqWGEaFzXz/HvoyaJG6cdXf/5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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