SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57d36c41afa4237bab5b7547a3b90b24b7092a659bd3c3e9ad425aa826fbddf9' 
  AND token = 'DHDxwMLCiwo/9OsziHtemk37Z72k9flf+ramjzFtZsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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