SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1cbce3a9cb93a092b81192d094cde5567011b35faca4565c183007f8537d1031' 
  AND token = '73TS+BxiAHQEiXf/XGoZI7TEp8SKga1LwrqLPERx81o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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