SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaffdb161c2ba85f7d1d01909cd1f67c4afdd4786688d72942170d8ae21c470f' 
  AND token = 'txqoZ0hxZedXSpwzPLDZokgPMVF3ZrvPLP11MFHDxuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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