SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b74bbc0961ea540ec29d05f642c75bd9b085170262aad3001995e6bfb36772' 
  AND token = 'eISw4AcIVGmSgsr+38N4Q8oMIV53GIDeOvLU1askIqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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