SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d87b2709dc5c42cc4d5e64fa6dc09cbadcd4e784450ce4e6720195def76f28b' 
  AND token = 'viFdz7j/emliDSQeqOmChB+dpSYWUkesVV93zB8jiBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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