SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5ce939f7fdddf20fa0884626e601d3819dd5150d1724033f7ab5689022dcfea' 
  AND token = '5lXplO/ZxiPya21YkgPRAoFZlEX+pkI4iyNnyyQKeAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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