SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28860bec8548316be8d872fc7efa53b2825cd410aca4738e82015e9b4945943d' 
  AND token = 'Ke31uGfCfkYVJXo7FeuN96pQ0mg27lYKabGKqMMUgks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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