SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0f1c45d8eb62a37574f26a084dc15e304b9e006df0bd6622c278f94a262db12' 
  AND token = 'IjiYgXzGGJ+X+D8AvMzuFmhYHvYTUdW46Nk3d9Z8nC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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