SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dcf5be4f113f5ef42634f2a98c85100a24751c7195b123c19e1c15c62c54a07' 
  AND token = '16vy7R1BegCEyleBPcCrAVbmbORn5/hPAtWZqm8lqNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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