SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98f043350db629e44074cc93be8b9816d008fe662aeb2f26ecdaf4e0363f5a4b' 
  AND token = 'tyr+iF8jYp55DtJXK5Ln9t501R3o60IEAXvzGZIpswY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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