SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f8c88da4876711d4630114981acac8dd29ba29a52875cd7e754d57ef0792f6f' 
  AND token = 'mHYl+gjAKu96+hHMcjJLbbEJb4HFsAKufsBTswYkcdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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