SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cecc07df555725b43bbfc0ccb90aa7c773ebc4e16a95ea36f606c2917ab8302' 
  AND token = 'FaDzw7RWKUtXMpOXHo3iSlMhqHmHXIFaQAQxmgzF/UY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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