SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb24d749cf7a7395b06ce209e8d9fbcee99f6c1b97f8949945d919c0a9ba6af9' 
  AND token = 'i75PAcGSbLZVug0vk2l+tUSQ+cXsMN4alVYx111xRNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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