SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c805d1335cb14f9a30a26ad2e025d3755d6619603647967295d49247e34686a' 
  AND token = 'bNW+RnR3U+f0ek1nBH8TgQy/wHntGHfhWUPszxz33lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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