SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc1d08311f07579e161f2a0e540c3ca73dd725e10bf4b0aa340f46f83f002b8a' 
  AND token = 'pSQMW8tHnOyqHMi9sQjFeIE0C2j+rjX0gz9FXx9p8Ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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