SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '892cf9198bb4f9457dad41a65486bad7bf04bfc8b23ef0a04cf534761248e044' 
  AND token = 'n0blj7mg3Q7ecrTcKk9hngi0ZabLfp6INSJn+QA1PGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}