SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e54bb0d08185889deecea13977476a772ac1a957449b387386f1771692e3c66e' 
  AND token = 'ZoVUZUAFLGuBj0JnyvXPvl2kjtv5oupPXVQB5zcJwT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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