SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd173257cb1fff6142abb93a08c9043f5e75df089013e4a7151dd967d0bd64035' 
  AND token = 'n0dVWjiSXYBHdVnyPQ8VEG6qSMpOvBzSEhkSsaS4gAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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