SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '730b5c96cdcf5c701547262c931acc412448e9ccbd797d305eb124d7827e8551' 
  AND token = '0lwk9J5ChJDr2XKih6dnm3KmR09xqcgJdWOHXDJInnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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