SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '844d9722595c8a8ffceeaf8bbc9895036a52df4128a7b25332adbb12383cb318' 
  AND token = 'xfkdWIQpZPi1+0v8NkAiV4J8dmecszWYQgj+vPCBvQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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