SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b4e79d40e6dcc34728124f18aab1d11aa2a81ed31a74076cb9151d1c14a5110b' 
  AND token = 'xl+pcILxWm39Zj11y0HS6vfyHsWDRtnvkbjiHRNsZUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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