SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d144cdb613d6146819b814205c20d11bdfdffbb124d07207f35ffe4e8024021' 
  AND token = 'w8Tg9QZBMvbz47YQDcVptD+czMIhEOqtFExHYeNFivA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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