SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce441f9b2f95d8f7ada745a4aa49a93b287fc5b8c9707b9bd4a19d5788f5145e' 
  AND token = 'OmyF/64FRgV08+QC9qQyTi8xAy1AFPBKrFAgYuP0ifk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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