SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1881df6ff6d0fa3e8db0083c789ac2e238ee014dad4290a6a84b7792b51e37d3' 
  AND token = '1ZSzuq0cFdK87FOA+RLtjfPAabcbTHo83ecnk7iUgBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}