SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90182632f348a48d9b3d8b5ec89d81cb231a158cd387389816572bff0d1931e7' 
  AND token = 'L9Ve/mXZOYhoxLHH1UAbsB5kWjlkPjgqDFh/2lEbJqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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