SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7df4b4fe5f894cd7f4be1dda39ef7c77566531ebce4c24548c6f24bee485337b' 
  AND token = 'occnO7Pqph8JcoXbbpeo1E0Pa4+mvAna2x6UuDzYpDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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