SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6f4a7bfe2e4ad56e75487d167a1cf22a36d77c0815a130acff97fa09e87ebc9' 
  AND token = 'sUaz63HEs5+K+N2xPuKRhIrew0/xPjIWUx8NU04Q0S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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