SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03045e20c393db5e80f778e0fdd874bc6220e9214f6988c1defbdf3299e65aba' 
  AND token = '7H6GKALNLTv/xF6dEwNMikkID4EiOcvGhJy4qckHpfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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