SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37c24bb916937787c20bd38f96342c81aa37d16e4f0780280e551cfb2ddd6124' 
  AND token = 'JmEb4gPEb00oI/YYw1g73r++sFOH86GYzXK5HKnmfxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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