SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3dd74bbf9cc042a4de21f3f1e4bb26c75ce351b6cb2462af70f07a67864cd63e' 
  AND token = 'XM9+15Zl2diYU7l5QbFjrIOu/POKfLaMMglvkJwfN68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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