SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94507995393efb901d2d6c5c96ae909a0665f3f102c228a58df032fc0e4b36cc' 
  AND token = '0+VS80pwgiL+tUSP/+6GKUkDEqJLQvUArV9ZICjJeUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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