SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65578f48a35ac4a13fe21d98942a175babb6a432c193e12f40974d3bbc2c346a' 
  AND token = '3EBxSDmolJi4KrdoEU8mIYyUVnDdLxdUA+ZtXxtdnS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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