SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7df2bb6d956cc4b66fb618c17558ba8f0a2025335310c17cbb13463874175341' 
  AND token = 'Jq4byfN8+cpbQ5bc/Ktjo9fvgxPPI7uDQzz/a5v+Z3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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