SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c0151081ec59bf7beb5bc71d65e9122053d0926547d0544dc4e4c02b006f1a' 
  AND token = '499/XOxPYBc5v0lqz2j3AgoV349UjnwRdlQSeZ7aSqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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