SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38d3d73ef76450c5bb980c3fb1840457613567703ec1eaa2dba691b2fc865536' 
  AND token = 'uoJn7R+8X91XXxqj7klXYK48uBE8dU/y1ERaUNYtOKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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