SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4191bcae0cba77b783312bfd1ca602baa246cab103945f540b91c3bc07628718' 
  AND token = 'gzzFSNBk1pKAJvm365Df1bkA5MK+0SDGxn9QZ5qAIEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}