SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8c67a20a85a15591f273701b60bf4ed54631796213c6cf4542ea6fae313177e' 
  AND token = 'OQ6pajOIUFrwSyCoKAlVLvfoYFEbOjhIIcfdoJqi6vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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