SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28aea9486e4041f8f5a19e726da94a1168078bfd9985f7c2f942ed3be6b53382' 
  AND token = 'GakVP+WV+XQvvpXkDiAqraeVGl6BsbYiHFkJ9qVj25g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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