SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87fda8c58740d65c380c36db2e9cb57354892b04889d2aef29c1034d220ed9a1' 
  AND token = 'n+mlhFTAd6eZLwY4BcblA/aZhM4rXEYwQWycYl0lIXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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