SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dc13e3ace636c847f32e6fbb6d558f41d0d2c4ac8811d596e0fbd3e180a98bb' 
  AND token = 'j5hMxOBDlIASthu6FL1uNCUkFjF9ZDFroB3VBjOglrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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