SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e2bd7d3ee3a4e6869cfee98489a7482ba50c9ff7e85c023e8f94fc3a1f6529' 
  AND token = 'i9aupWF+n3sHmFBczYK7DuOIJNtBsYgSG70ztVWQ+sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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