SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db4c73cc93fc4bba24d4bcea0f910b3053590941659b165a1a6253eb29b05f2' 
  AND token = 'qRUzmFEIq0yPwSzuc1YeknBIlsSyekZoY9+flSFsJMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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