SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72f4e1e5cf52e3a11c27c7f3b149acef4e1ec01106f154284e044058fa620b96' 
  AND token = 'rGvUj2+78R/0HOsAIBZ9xwSX9+VOGCFzPKoKxlzb6AA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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