SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f53fe3d785fc3d24e3677b48027705113537366d4fb25a15999c728ea0d4196b' 
  AND token = 'I0/QUp27f24Jh+DLhBJboqQtkNzj/m64sX0AX5XZ/Eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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