SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f0635ba96ff814f66c4befa197dab7f68cd2f9ecfc58a1180a2a3912ba54565' 
  AND token = 'duzbMR76Wi5m1CjqraEy3xD4ws4yAF+sWomeBEwDags=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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