SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca7f0921bb1d8ab88abdb0fa3fb1c50e18bec18d356a2568e90a4f861f865232' 
  AND token = 'T5WhPPeZAh37sgKgZQj7KMSkpVAEFOvt/GxDxcydO4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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