SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5964a392d20d93b36866c9a9df7a3a4b5868ab80a43183cc677deddfcf6c3763' 
  AND token = 'iXwJ/rIx+7AnT1KYEq/hEh30d+W45LtDMUuGDgiWtVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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