SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d1ef87126372e03052ba213ff1d69b1a397140b15eef89be472fea0bafcad5e' 
  AND token = 'bnU4doCInhmr5tfc2zEjl6CMzxI9XHMswiayI2RuetE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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