SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e45f139bc6622c619d16d8a7bd5793108f2fad50ac67d5ff690828da65178f5' 
  AND token = 'Wr0C6PuOsao2Z1s7MNogTOq3MhGb0iP3nuixW9iVquQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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