SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cdbd8e3685a45bc808a35d8a971e17814ff041a6a1fccb00d4507f1f759b826' 
  AND token = '5Q3HtwodHutSdlsPhCwASs6pHIQ3f/c8yRDqRu3D0Go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}