SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f16a15b91db1659927a92bdd2332d874fa8d8b082283b6f88783739135ce706' 
  AND token = '8eYWL/puYoD1S0VpWz/ZKmceYNcrnpLmrfXUEYiL+A0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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