SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5438a3a965d6b2fcc71df5203c35e5fe4494539e55371413fada9f5db931752c' 
  AND token = 'TjW5IiSv/E03OB4bKhDM1r+OHpzauBFG9DX9yyjX+a0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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