SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b2d25be74b63491edacfb303da1332fd47e79b1c54edca9ba74e768c17f47a2' 
  AND token = 'TaoysHv65IWqmYpCoB15AjjyGUnUFK+Z6z9JryqTF2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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