SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3507323391344659572c48015792e1baaa198ec1fa35bd3c9f8da79a0d56b33b' 
  AND token = 'aq9caPmm7mOfFEOpoS+/sFIGWnBbZj+MWovaYwnqKUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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