SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e8c6ffb41b9899dfc8233f7cf5070de01affb95663a9abefe5f5aff9bc6853e' 
  AND token = 'pVRQRCAkb3mm+yyzQLN8yry9Z4paopykxJMXZZclByw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}