SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aec978de196fd7695ac8197fdbbd6cccb90107ad738b706a9bd6baf953ec735f' 
  AND token = 'tbfxVB3qHfmQed5g5gSoTFBCcByefBoQzPEagYtUcLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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