SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b7fd892045f4455b1f026b250683e94ee61806524683279831254a253f0b66a' 
  AND token = 'JJQ0PREmlSPBBPvRN+vIinaDkdCUT/snNtSGp0A/FKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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