SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'feefcd80d549de09767aeee9b00d83d02c2ca01916ecd86e4c5b878a1ef75915' 
  AND token = 'KLcoZId3LHxVjbnexDvE+D4Wv4ghU9yu4El4FlVTWbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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