SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48dbb520a946ce27b5e529aa06fae3c4e85182931f1bcbe775c48fe7dc94216a' 
  AND token = 'NrSNI38JGYBIJFNukYnrifJWgTL/5ybuiEzGe9LqXxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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