SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cee5c5404d42ea33ecdde184a5773adf9daa9b143e72060d9a6018417609cb07' 
  AND token = 'K+p56awUVTjegAJcCYskzpgN/bkKUwgOrmCiTKgPoUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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