SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e08ae4601e10593c04ce6e422651d1c18ba62d37f71cbcc39d5fb2d33b66aab0' 
  AND token = 'ZMyH1+86ypEHCjvs8xjmihRqLswYxzRGCyvLmD6XETM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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