SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1102aea9dc3ec4deacc16527beafe0db6a62032f0f863dd181546426e5ee256' 
  AND token = '6jXnYF3SNp3tiTJzncSD+En3Zk+TbdXOmGVVeGCP94s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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