SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90bea94ed4953b83e19f2e0936211d2f84abfe9afdf46969987fe60834ef7bd2' 
  AND token = 'D180T3hBYeMx9gGbJBm+G6TuGeHhwGXjXDgbGyGw5XY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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