SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7fa004bdfee0fea70c3c526c0f508104a18984a8585a550857738e625caac10' 
  AND token = 'saDb8vSlTLu6uPbegoGrn99TF/ZaWBjOyDZYN9xI+Es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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