SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66a7ba85233f0c1cb2650e061a8f25e8502ec7d5cc9869e058fd279465a9b2ae' 
  AND token = 'nfDtCFICSliJucFSBdeVCY9Q4mzEyK1peyDkoP/H8QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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