SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4313ba112856da82b22d6fc2d7c670bffa648e9a54e84a50ec088b59f20fb955' 
  AND token = 'wy+sdGTGbrokGTyL2UTZ7WqtSjwiCSy4A+trE2XeGwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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