SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf9c16f186fe0d956cf9894fa2ef9feef8cdcc614a41e5988938d9d11aa9d140' 
  AND token = 'rF1jwhozA2G5NFSRI/zCQkpOJJP1kOA2aOooGH0YRMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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