SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e69adf0da8b38ad0b071671b83a192658239b24700b322f9383b86d3bcaf93' 
  AND token = 'GRp1bclThGFyfHLtG67O3NjwSGtehSf2hU/1HLuPfmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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