SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c53d74fb3286d6b8fd34b899adbb225c10546229ca73462fbd3dd597c347ee99' 
  AND token = 'Dahsz7qAmpCM+vDEtFI5WVNXCPYxbNUedqcKrMcLS7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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