SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a67985509258b1bc6ac6fdd9340c48103ce5a54cfd36ac55f96bb6249dcfc00' 
  AND token = '1u25VDBHHDRmOw+2bjPK6mgQPOIh+HlQTjoxb2xQEoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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