SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d64f6659e510d170bb8e8727984bbcc85d3941cdadd3ebfdd168098d7cac65' 
  AND token = '1NAxA3fjNTyeBNdT78+UwwvLcxrUKeC4CVffCCLf+NA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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