SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'facdce3fdb4dfaaf5d2a528c905bd0a19d121bde6b598b9ac4b33ca5252dd901' 
  AND token = 'zydvj8oLr/ZE1HMKvkzrJPUvALDNceGDxmIpOZTAJ+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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