SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87a32d8a736860989e17cf277d16a51ce2c3d814fc104b398d68cb176ca782e6' 
  AND token = 'JcO6PP6V7mAPod+zhM8bgpzi+lt13NzEKfVJ3E54KXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}