SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c296f0364acb7038f958d37f2965ac1a1da50e537badaaca0dc60a449864237b' 
  AND token = '8ojyNjq8nMrK7y51OwRw34Mr5EbAlT3GX0+DD8fNUSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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