SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e6dfebf76555f150023122f34e3d8a5575ea62a2332bb494bc70b0bb15c542' 
  AND token = 'oeqNHMzRsIiqSiCGcKa2KaKUg0bnV7bjwnqNQa098s8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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