SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd619c8bf37cd391a554a84c71ffce6c523817caf0e77aa00f0a848f8442cb335' 
  AND token = '/mwuaKm9Gof/AdZPfJ1kMkvwwFsxZLtxz+2ulEyNU+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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