SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fae816b62fad8597c597c32be2d656f6decefb20eab5b2432ec855bc34fa48e1' 
  AND token = '4ivhEvOr3gunpyadW2IyMmBvPojl9y1jBf7FmsL0TdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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