SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24322482e504c101b5b142848e210c5abada0f6c13400aa56919b586d02fb6bf' 
  AND token = '0gLvnibSnrY2+aY4jJFQxGEgDu2SkCAuq/ZBv2cGafk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}