SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fc17a7880a35944398276e4e47cf9ed4f483f5cbe395ed082d1eea5c6c40123' 
  AND token = 'XWJ/Oztne3WbKhfN+5cbYyqCNibiBiDXIKdCYJLTOUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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