SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d2c09e6697dccef33593dff4ba04655c9671c072a4580c86283725eb9a94b52' 
  AND token = 'rjd/zCHOiaNdwZW5/+qXfahUB75s0N++TafzOAcWjmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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