SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6cfea413b7db45bce13af9099798df9071bbc8f09db97d426f840a80ce1baf5' 
  AND token = 'GJKEPcMC609DKJylh3xt+7AiaX5kpQtVmBune+Xwib0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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